This invention relates to a novel resin for use in coalescing oil from an oil-water liquid dispersion and to a method of forming the resin. Also, it relates to the method of separation of the oil into a layer using the resin.
It is known that the passage of an oil in water dispersion through a bed of hydrophobic polymer resin granules serves to remove some of the oil from the dispersion. The mechanism is such that the oil is attracted to the surface of the granules and is retained thereupon while the water is repelled from the same granules. The granules have been formed of materials including polyethylene, polypropylene, polyvinyl chloride, polyvinylidene chloride, and Teflon (polytetrafluoroethylene). However, since substantial amounts of the removed oil is retained upon the granules, it is necessary to clean the bed frequently, a costly and time consuming operation. Also, the effluent from the system has a relatively high oil content in comparison to the projected strict environmental standards for discharge. For example, in U.S. Pat. No. 3,654,944, using polyethylene granules, the most efficient oil removal in such a system is stated to be 19 ppm.